1. Field of the Invention
This invention relates to pseudonoise (PN) spread spectrum codes. More specifically the present invention relates to a method of jumping a composite PN code so as to enhance reacquistion.
2. Description of the Prior Art
Heretofore when it was necessary to reacquire a PN code it was necessary to search through the code from chip to chip until the code being acquired was in synchronization with the receiving PN generator. It was possible to either speed up the PN generator in the receiver or to slow down the PN generator in the receiver. Long codes can be as long as 10.sup.10 chips long and the repeat time for such long codes can be a matter of days. Thus, if a long code is completely out of sychronization and no history of the last synchronization has been kept it is necessary to search a code that can be so long as to require days for synchronization.
Long codes can be made by combining shorter codes to create composite codes. Composite codes if made by properly combining component codes can not be distinguished from a unique individual long code. The present invention is concerned with a long composite code which was made by properly combining a plurality of composite codes. Heretofore the only way known for searching either individual day long codes or composite long codes was by searching each individual chip as mentioned herein before. It would be extremely desirable to be able to adjust the PN code generator in the receiver so that it would be substantially in sychronization with the PN code being received before a sychronization search is initiated. If such accomplishment could be achieved it would save hours or even days in resychronizating PN code generators during reacquisition.